#include <stdio.h>

void swap(int *a, int *b) {
    int temp = *a;
    *a = *b;
    *b = temp;
}

int main() {
    int x, y;
    scanf("%d", &x);
    scanf("%d", &y);

    if (x < 0 || y < 0) {
        printf("Invalid Input");
        return 0;
    }

    swap(&x, &y);

    printf("%d, y);
    printf("%d", y);
    return 0;
}